Abstract:
objective: to assess the impact of atmospheric pollutants on the respiratory health of children of different age groups in juarez city, chihuahua, mexico. material and methods: data on emergency room visits between 1997 and 2001 for respiratory diseases in children less than 17 years old were obtained from hospitals in the juarez city belonging to the mexican social security institute (imss). diseases were classified into three groups according to icd 9th and 10th codes: a) upper respiratory diseases, b) lower respiratory diseases, and c) asthma attacks. this information was stratified by age group (<=5 years and >5 years). daily air pollution data (ozone and pm10) and weather conditions were obtained from the monitoring network system in juarez city. statistical analysis was carried out using a generalized additive model assuming a poisson distribution. results: ozone concentrations, but not pm10, were statistically associated with emergency room visits for respiratory diseases, mainly among children 5 years old or younger. in this group, an increase of 20 ppb 1-hr maximum for ozone was associated with an increase of 8.3% in the number of emergency room visits for upper respiratory diseases, with a 3-day exposure lag; and an increase of 12.7% in the number of emergency room visits for lower respiratory diseases when considering a 4-day exposure lag in a maximum 8-hr mobile average. the largest effect for the complete sample and for the group 6 to 16 years of age was observed for 3-day lag (5.1% for an increase of 20 ppb 1-hr maximum for ozone). for the 6 to16 year old group we did not find a significant effect. conclusion: the wide range of risk is quite important and might represent a substantial cost for the health system as well as for the society. our results emphasize the need to implement preventive and control measures for air pollution and avoid the worsening of the present situation.

Abstract:
objective: to assess the relationship of ￡10 μm particles (pm10) and atmospheric ozone concentrations, with the daily number of emergency visits due to asthma and acute respiratory diseases, among children aged under 15, living in ciudad juarez, chihuahua, mexico. material and methods: between 1998 and 1999, an ecologic study was conducted. atmospheric data were obtained from the environmental protection agency (epa), from eight monitoring stations located in ciudad juarez, chihuahua, and el paso, texas. from july 1997 to december 1998, data from emergency room visits for respiratory illness were abstracted from existing medical records of two mexican institute of social security (imss) hospitals in ciudad juarez. diagnoses were classified into two groups: a) asthma, and b) upper respiratory infections (uri), according to the international classification of diseases (icd-9 and/or idc-10). statistical analysis was carried out using the poisson regression time series method. results: during the study period, the mean 24-hour pm10 level was 34.46 μg/m3 (sd=17.99) and the mean ozone level was 51.60 ppb (sd=20.70). the model shows that an increase of 20 μg/m3 in the mean 24-hour exposure to pm10 was related to an increase of 4.97% (95% ci 0.97-9.13) in emergency visits for asthma, with a 5-day lag, as well as to an increase of 9% (95% ci 1.8-16.8) when a cumulative 5-day exposure was considered. uri increased 2.95% as a cause of emergency room visits, for each 20 μg/m3 increase in the mean 24-hour exposure to pm10. the impact of pm10 on emergency visits for asthma was greater on days with ozone ambient levels exceeded 49 ppb (median value). conclusions: a positive association was found between environmental pm10 and ozone concentrations and the daily number of emergency room visits due to asthma and acute respiratory diseases, even with levels lower than the mexican standard levels. also, a synergic effect between pm10 and o3 was found.

Abstract:
calcium metabolism of the mother is modified during pregnancy because of the mineralization of the fetus skeleton. objective: to evaluate the association of calcium intake and bone demineralization during pregnancy. material and methods: at each trimester of pregnancy a validated food frequency intake questionnaire was administered to assess individual daily calcium intake in a cohort of 206 pregnant women, residents of mexico city. samples of urine were collected to measure levels of the cross-linked n-telopeptide of type i collagen (ntx), which is a biomarker of bone resorption. the association between calcium ingestion and bone resorption was analyzed using random effects models; non-linear associations were explored using generalized additive models. results: progressive increases in ntx levels were observed during pregnancy; with mean and standard deviation (sd) values during the first, second and third trimester of 76.50 (sd=38), 101.02 (sd=48.86) and 144.83 (sd=61.33) nmol bce/mmol creatinine, respectively. higher dietary calcium intake was associated with lower bone resorption (β=-0.015; p<0.05). the association between age and ntx showed a non-linear trend with an inflexion point around 33 years: increase in maternal age below that point was associated with a decrease in bone resorption, while in older women the increase in age was associated with an increased resorption. conclusions: our results suggest that calcium ingestion, specifically from dairy products, reduces bone resorption during pregnancy. for each 300mg (a glass of milk) of calcium intake there is an estimated reduction in ntx level of 4.8 nmol bce/mmol of creatinine (p<0.05).

Abstract:
objective: to determine the effects of lead exposure on the time elapsed to become pregnant. material and methods: the study population consisted of 142 women residing in mexico city between 1997 and 2001, who were already participating in a study to evaluate effects of lead exposure on reproductive health. measurements of lead in bone were performed when women were first admitted to the program. information on lead exposure and other variables of interest was obtained through a questionnaire. participants were followed up to assess the relationship between the time required to become pregnant and lead exposure. statistical analysis consisted of kaplan-meier estimates and cox proportional hazards models. results: of the total number of women in the program, 42 got pregnant: 34 before the first year of follow-up, and 8 at a later date. the mean value for lead concentration in blood was 9.3 μg/dl. the mean values for lead concentration in patella and tibia were 16.0 y 11.0 μg pb/g of bone, respectively. survival analysis was performed and no differences were detected in blood lead levels and time to pregnancy in the first year. nevertheless, in women with blood lead levels above 10.0 μg/dl, the likelihood of not achieving pregnancy was five times higher (95% confidence interval [ci] 0.05-0.56) after one year of follow-up compared with women with blood lead levels below 10.0 μg/dl. conclusions: exposure to high lead concentrations may be an important risk factor influencing the time period for a woman to get pregnant, especially in fertile women who have tried to get pregnant for more than a year.

Abstract:
Levels of enzymes that determine testosterone catabolism such as CYP3A4 have been associated with prostate cancer (PCa) risk. Although some studies have related CYP3A4*1B allele, a gene polymorphism that modifies CYP3A4 expression level, with PCa risk, others have failed, suggesting that additional genetic variants may be involved. Expression of CYP3A4 is largely due to the activation of Pregnane X Receptor (PXR). Particularly, rs2472677 and rs7643645 PXR polymorphisms modify CYP3A4 expression levels. To evaluate whether PXR-HNF3β/T (rs2472677), PXR-HNF4/G (rs7643645), and CYP3A4*1B (rs2740574) polymorphisms are associated with PCa a case control-study was performed. The multiple testing analysis showed that the PXR-HNF4/G polymorphism was associated with higher levels of prostate-specific antigen (PSA) in patients with PCa (OR = 3.99, p = 0.03). This association was stronger in patients diagnosed at the age of 65 years or older (OR = 10.8, p = 0.006). Although the CYP3A4*1B/*1B genotype was overrepresented in PCa patients, no differences were observed in the frequency of this and PXR-HNF3β/T alleles between controls and cases. Moreover, no significant association was found between these polymorphisms and PSA, Gleason grade, or tumor lymph node metastasis.

Abstract:
It is of common knowledge, that mentally ill patients are frequently subjected to physical and mental abuse. However, there is little information about this topic. Patients with mental disorders may be subjected to physical, sexual, psychological, and economical, as well as, negligence abuse by folks and people from community, due to fact, of prejudice towards people with mental disorders. Therefore abuse in all forms, constitutes an additional stressor event and changes prognosis of preexistent disorder. Diagnosis of abuse is a complex process and it is necessary a full clinical history, including physical and mental evaluation.

Abstract:
Major depressive disorder (m d d) is the disorder with the most important global burden in terms of disability-adjusted life years. Objetive: to determine the current prevalence of m d d in the general population in Bucaramanga, Colombia, and to explore the risk factors associated with them. Methodology: this is a cross-sectional survey with a population random sampling that involved 18-65 year-old people living in Bucaramanga. A psychiatric diagnosis of a m d d during last month was accomplished using Structured Clinical Interview for Axis I diagnoses (s c i d-i) according to the d s m-i v-t r criteria issued by the American Psychiatric Association. Results: a total amount of 266 people were selected (57,1% women). Their mean age were 37,4 years and the formal education years were 9,8. A total of 12,0% was unemployed, 56,1% had a stable couple, and 51,2% lived in medium socioeconomic strata. The prevalence of m d d was 16,5% (95% c i 12,3-21,6). A significant association was identified between the fact of not having a stable couple (p r = 2,11) and the and level of education (p r = 0,41, for 6-11 cursed years, and p r = 0,28, for 12 or more cursed years, compared to five or lesser years of schooling) and the m d d. Discussion: the current prevalence of m d d is high among adult general population from Bucaramanga. This implies the necessity to develop better strategies for an early detection and an integral treatment of m d d cases in order to decrease social and economical costs of m d d.

Abstract:
a taxonomic checklist for fish larvae and juveniles occurring at yalahau (june 2001-may 2002), celestún (july 1994-june 1995), chelem (july 1999-june 2000) and río lagartos (november 1996- october 1997) lagoons located in the northern part of the yucatán peninsula is presented. sampling was carried out for 5 minutes using a zooplankton net for larvae, while a renfro net was hauled for 50 m2 to capture juveniles. this work aims to provide the current state of the taxonomic composition and general distribution for 34 377 fish larvae and juveniles. our samples represent 2 classes, 17 orders, 45 families, 83 genera and 117 species were caught, including 39 new records, where 24 have been found only in the gulf of mexico, 3 in the caribbean sea, and 90 are common to both regions. this study updates and increases the number of species in larval and juvenile stages previously reported. it was found that early reef larval stages were more abundant towards the east of the yucatán peninsula and less to the west. the high number of shared species (90) suggests that the northern region of the yucatán peninsula is a transition zone for fish larvae and juveniles between the gulf of mexico and the caribbean sea.